Compose file versioning in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the version field in a Docker Compose file?

The version field specifies the Compose file format version, which determines the syntax and features available in the file.

intermediate

Name two common Compose file versions and one key difference between them.

Version '2' supports networking and volumes with some limitations, while version '3' adds support for Docker Swarm and deploy configurations.

beginner

How do you specify the Compose file version in a docker-compose.yml file?

At the top of the file, add a line like: version: '3.8' to specify version 3.8 of the Compose file format.

intermediate

What happens if you omit the version field in a Docker Compose file?

Docker Compose assumes version 1 format, which has limited features and is deprecated in newer Docker Compose versions.

beginner

Why should you choose the latest stable Compose file version compatible with your Docker Engine?

Using the latest stable version ensures access to new features, better performance, and improved compatibility with Docker Engine capabilities.

What does the 'version' field in a Docker Compose file control?

A The container image version

B The Docker Engine version to use

C The Compose file format and features available

D The network driver version

The 'version' field defines the Compose file format version, which controls syntax and available features.

Which Compose file version introduced support for Docker Swarm deploy configurations?

A Version 2

B Version 3

C Version 1

D Version 4

Version 3 added support for Docker Swarm and deploy configurations.

If you omit the version field in a Compose file, what version is assumed?

A Version 1

B Version 3

C Version 2

D No version is assumed

Omitting the version field defaults to version 1 format.

How do you specify Compose file version 3.8 in your docker-compose.yml?

A version = 3.8

B compose_version: 3.8

C file_version: 3.8

D version: '3.8'

The correct syntax is: version: '3.8' at the top of the file.

Why is it important to use a Compose file version compatible with your Docker Engine?

A To avoid syntax errors and use supported features

B To speed up container startup time

C To reduce image size

D To enable GPU support

Compatibility ensures the Compose file syntax and features work correctly with your Docker Engine.

Explain the role of the version field in a Docker Compose file and how it affects your configuration.

Think about how different versions enable different features.

Describe the differences between Compose file versions 2 and 3 and when you might choose one over the other.

Consider the use of Docker Swarm and advanced deployment features.